1. Field of the Invention
This invention relates generally to bubble traps for eliminating gas bubbles from a flow of blood or transfusate through a fluid line.
2. Related Art
Conventionally, bubble traps comprise a wall defining a chamber, with an inlet providing fluid flow into the chamber and an outlet providing fluid flow out of the chamber. Generally, the inlet and outlet are separated by an expanded chamber volume to establish a low velocity flow path for the fluid traveling between the inlet and outlet. As the fluid flows from the inlet to the outlet, the bubbles within the volume of fluid generally rise to a gas dome within the chamber to be vented from the chamber. Conventionally, bubble traps must be maintained in a specific orientation to enable the bubble trap to function effectively. Otherwise, if the bubble trap is skewed from its proper orientation, the bubbles within the flow of fluid can not be removed from the flow of fluid, thereby negating the purpose of the bubble trap.
Additionally, bubble traps containing a valve vent must be purged of bubbles periodically by manual or automatic intervention. Some bubble traps contain a gas permeable hydrophobic membrane barrier between an inner surface of the chamber and an exterior ambient environment. In these devices, the pressure within the fluid path is greater than the ambient environment, thus forcing the bubbles through the gas permeable hydrophobic membrane. These devices, though largely effective in their purpose of removing bubbles from the flow of fluid, potentially allow air to ingress into the fluid flow path if the pressure within the chamber is less than the ambient pressure, thereby negatively impacting their intended purpose of removing bubbles from the fluid flow path.